Orifice Tube problem

[justacruzr2]

How far into the evaporator line (the upper one with the dimples) is the orifice tube supposed to go? I assume it should go in until the end of the orifice tube is even with the end of the evaporator line. If it doesn't, the line from the condenser that connects to the upper evaporator line won't go on. Yet, the last time I inserted it into the line I had to force it in until it was even with the end of the evaporator line. That didn't seem right but I was able to connect the condenser line. After the system was evacuated and charged I still wasn't getting cold A/C. And the orifice tube was pushed all the way to the end of the line where it makes a 45 degree turn into the evaporator. It took me about 1 1/2 hours to get it out even with using the Robinair orifice tube removal kit. The orifice tube is a 38623 or T38623 which from our catalog (I work at Advance) and everything I see on the internet is the right one. Those dimples, I believe, are meant to be stops so the orifice tube can go no further. If I push it in until I hear (and feel) a click, which I assume is the tube locking into those dimples, it's still too far out for the other line to be connected. If I force it in like last time, it has gone past those dimples and now nothing is preventing it from being pushed down the line. This changes where the transition from liquid to gas takes place. I have been told that under normal circumstances the orifice tube should be easy to insert and remove. I have checked the evaporator line for any obstructions and found none. What's going on here? Is that orifice tube some generic universal replacement for the original and may not work in all cases? I have tried 4 times to get this A/C system going with no luck. The compressor is new, the accumulator is new, and the evaporator, condensor and all lines have been flushed out. I have also checked this against another evaporator I have and the orifice tube only goes in the same distance with the end still hanging out. This is an 84 Grand Prix in case that makes any difference although I think all the Gbodys use the same A/C system. Frustrated!

 

[383_StealthRam]

Amazon.com

Here's mine before and after, HTH

 

[383_StealthRam]

Summit Racing even cheaper, includes orifice tube...I think they come with or without...

 

[justacruzr2]

Hey guys, thanks....great idea. So I guess I'm not the only one to run into this problem..

@ 383_StealthRam

Did you have to re-bend that line from the condenser? Mine runs along the bottom edge of the fender apron and then turns up and has that shepherds hook bend.

 

[383_StealthRam]

Nope, not at all...or maybe very slight tweak to line it up. You want to cut the EVAP inlet tube behind the existing dimples for the original orifice tube, then the repair fitting should end up approx in same spot.

I show pics of before n after in my first post.

HTH

 

[383_StealthRam]

By the way you're sure you've been installing the orifice tube in the right direction? Their should be an arrow on it that points to evap IN direction, see pic below.

The end that with the screen faces out, towards the condenser line; the side towards the EVAP has shorter distance to it's end from the o-ring. Forcing it in backwards could explain why you may have had so much trouble with it. In the summit pic it's oriented properly next to the repair fitting.

 

[justacruzr2]

Thanks for that info. Boy do I feel stupid right now. I've been inserting it in the wrong direction. My first time working with A/C and I'm learning all about it. All my other cars are older and don't have A/C. I really appreciate that heads up and it probably explains why I haven't been able to get cold A/C up to now and why inserting it in the wrong direction leaves too much hanging out. Your the best!

 

[69hurstolds]

Think about it this way. The filter screen catches the incoming from the condensor line. So the screen should always face away from the evaporator. Of course look at the arrow when all else fails.

 

[383_StealthRam]

Thanks for that info. Boy do I feel stupid right now. I've been inserting it in the wrong direction. My first time working with A/C and I'm learning all about it. All my other cars are older and don't have A/C. I really appreciate that heads up and it probably explains why I haven't been able to get cold A/C up to now and why inserting it in the wrong direction leaves too much hanging out. Your the best!

Cool, glad it was just that simple...usually things are. The thing about it is having the tube in backwards will still actually work, but be much less efficient and definitely not blow as cold.

I actually rebuilt my entire AC system couple of years ago, replaced pretty much everything except the Evaporator which I simply reverse flushed. They rarely fail, or leak from that era in my experience so I didn't feel the need to replace it. The parallel flow condenser is a must imho with new compressor and r134a conversion. Also gotta get good airflow across the radiator and condenser or system will not perform well either.

Mine get's almost down to freezing (see vid) at the outlet vents temperature, and my HI side pressures barely ever go over 200psi. Having the Holley EFI, I actually input the AC Hi Press sensor in, and use it along with Coolant Temp to PWM control the brushless SPAL fans. Gonna be doing another similar full rebuild on my buddy's 86 Monte SS soon, just waiting on all the parts to come in.

In addition to the behind the radiator, shrouded dual brushless fans controlled with PWM by Holley EFI...I also have a PUSHER fan mounted on the front of the condenser that operates separately based on TRINARY switch. When I first turn in the AC, the PUSHER fan will come on immediately at half speed, then if the hi side pressure goes up over 254psi (which it usually does on initial turn on) it then bypasses the resistor and goes to full speed.

90% of the time, once the PWM fans come online, and the Hi pressure drops under about 200psi, that pusher fan pretty much just stays at half speed thereafter. The video about was from one of the most recent super hot low 90 degree days we've had in the northeast.

 

[justacruzr2]

Think about it this way. The filter screen catches the incoming from the condensor line. So the screen should always face away from the evaporator. Of course look at the arrow when all else fails.

Never even knew about the arrow. I wish I had paid attention to the orientation when I removed the old one.